To define the extent of shedding of respiratory viruses and Mycoplasma pneumoniae among a population of pediatric patients admitted to the hospital during a winter epidemic period and to identify nosocomial infections within this population.

An open, prospective survey of patients admitted to three wards (General Medical, Respiratory Infectious, and Infectious Diseases) of a pediatric hospital during a defined three-month period.

All patients with medical, respiratory, and infectious conditions admitted to three wards of the Adelaide Children's Hospital had nasopharyngeal aspirations performed at the time of admission with the purpose of documenting viral and M pneumoniae shedding. Patients were monitored daily for the development of symptoms of respiratory infection or new symptoms of respiratory disease. Such patients underwent a further nasopharyngeal aspiration for the purpose of diagnosing hospital-acquired infection.

Nasopharyngeal aspirations were obtained from 601 patients. Forty-seven percent of asymptomatic patients were positive for a respiratory virus or M pneumoniae, and 61% of patients with respiratory symptoms were also positive. Gastroenteritis patients shed viruses in 66% of cases. Respiratory symptoms were initially overlooked by admitting physicians but subsequently identified in 110 cases, and 46% of these were found to be positive for a respiratory virus or M pneumoniae. There were 18 possible hospital acquired infections among the 293 initially virus-negative patients. Multiple isolates were obtained from a substantial number of patients, especially those with respiratory symptoms.

A substantial proportion of all patients admitted to a pediatric hospital during winter represent a potential source of infection, and strict infection control measures should be enacted to limit the spread of these infections.

To evaluate measures intended to reduce Legionella infections in patients undergoing bone marrow transplantation (BMT).

Ongoing clinical and microbiological surveillance for Legionella colonization or infection was undertaken. All neutropenic patients with pulmonary infiltrates and fever unresponsive to broad-spectrum antibiotics were tested for Legionella organisms.

A 505-bed medical-surgical hospital with a designated BMT unit.

Two hundred twenty-five patients underwent BMT; 201 were treated on a new BMT unit. The incidence of Legionella infections was compared to that seen in an estimated 150 neutropenic patients treated on other units.

A combined approach to decontamination of a hospital water supply was assessed. This included heating, particulate filtration, ultraviolet sterilization, and monthly pulse hyperchlorination of water supplied to the BMT unit. The incidence of Legionella infections was assessed on the BMT unit and compared with the frequency elsewhere in the hospital.

There were only three cases of Legionella pneumonia among 201 patients undergoing transplantation on a new BMT unit. In contrast, 33 cases of Legionella infections were detected from approximately 150 patients treated on general medical floors.

A multifaceted approach to decontamination of a hospital water system led to a marked reduction in Legionella infections.

To determine the impact of recurrent Clostridium difficile infection (RCDI) on patient behaviors following illness.

Using a computer algorithm, we searched the electronic medical records of 7 Chicago-area hospitals to identify patients with RCDI (2 episodes of CDI within 15 to 56 days of each other). RCDI was validated by medical record review. Patients were asked to complete a telephone survey. The survey included questions regarding general health, social isolation, symptom severity, emotional distress, and prevention behaviors.

In total, 119 patients completed the survey (32%). On average, respondents were 57.4 years old (standard deviation, 16.8); 57% were white, and ~50% reported hospitalization for CDI. At the time of their most recent illness, patients rated their diarrhea as high severity (58.5%) and their exhaustion as extreme (30.7%). Respondents indicated that they were very worried about getting sick again (41.5%) and about infecting others (31%). Almost 50% said that they have washed their hands more frequently (47%) and have increased their use of soap and water (45%) since their illness. Some of these patients (22%–32%) reported eating out less, avoiding certain medications and public areas, and increasing probiotic use. Most behavioral changes were unrelated to disease severity.

Having had RCDI appears to increase prevention-related behaviors in some patients. While some behaviors are appropriate (eg, handwashing), others are not supported by evidence of decreased risk and may negatively impact patient quality of life. Providers should discuss appropriate prevention behaviors with their patients and should clarify that other behaviors (eg, eating out less) will not affect their risk of future illness.

Infect Control Hosp Epidemiol. 2017;38:1351–1357

To describe the procedures used during an influenza immunization program and the use of a randomized survey to quantify the vaccination rate among healthcare workers with and without patient contact.

Influenza immunization vaccination program and a randomized survey.

Johns Hopkins University and Health System.

The 2008/2009 Johns Hopkins Influenza Immunization Program was administered to 40,000 employees, including 10,763 healthcare workers. A 10% randomized sample (1,084) of individuals were interviewed to evaluate the vaccination rate among healthcare workers with direct patient contact.

Between September 23, 2008, and April 30, 2009, a total of 16,079 vaccinations were administered. Ninety-four percent (94.5%) of persons who were vaccinated received the vaccine in the first 7 weeks of the campaign. The randomized survey demonstrated an overall vaccination rate of 71.3% (95% confidence interval, 68.6%-74.0%) and a vaccination rate for employees with direct patient contact of 82.8% (95% confidence interval, 80.1%-85.5%). The main reason (25.3%) for declining the program vaccine was because the employee had received documented vaccination elsewhere.

The methods used to increase participation in the recent immunization program were successful, and a randomized survey to assess participation was found to be an efficient means of evaluating the workforce's level of potential immunity to the influenza virus.

The purpose of this study was to describe patterns of infection or colonization with antibiotic-resistant gram-negative bacilli (GNB) in hospitalized children utilizing an electronic health record.

Tertiary care facility.

Pediatric patients 18 years of age or younger hospitalized from January 1, 2006, to December 31, 2008.

Children were identified who had (1) at least 1 positive culture for a multidrug-resistant (MDR) GNB, defined as a GNB with resistance to 3 or more antibiotic classes; or (2) additive drug resistance, defined as isolation of more than 1 GNB that collectively as a group demonstrated resistance to 3 or more antibiotic classes over the study period. Differences in clinical characteristics between the 2 groups were ascertained, including history of admissions and transfers, comorbid conditions, receipt of procedures, and antibiotic exposure.

Of 56,235 pediatric patients, 46 children were infected or colonized with an MDR GNB, of which 16 were resistant to 3 classes and 30 were resistant to 4 classes. Another 39 patients had positive cultures for GNB that exhibited additive drug resistance. Patients with additive drug resistance were more likely than patients with MDR GNB to have had previous admissions to a long-term facility (8 vs 2; P = .04) and had more mean admissions (7 vs 3; P <.01) and more mean antibiotic-days (P < .01 to P = .02). Six patients with additive drug resistance later had a positive culture with an MDR GNB.

An electronic health record can be used to track antibiotic class resistance in GNB isolated from hospitalized children over multiple cultures and hospitalizations.

To determine which comorbid conditions are considered causally related to central-line associated bloodstream infection (CLABSI) and surgical-site infection (SSI) based on expert consensus.

Using the Delphi method, we administered an iterative, 2-round survey to 9 infectious disease and infection control experts from the United States.

Based on our selection of components from the Charlson and Elixhauser comorbidity indices, 35 different comorbid conditions were rated from 1 (not at all related) to 5 (strongly related) by each expert separately for CLABSI and SSI, based on perceived relatedness to the outcome. To assign expert consensus on causal relatedness for each comorbid condition, all 3 of the following criteria had to be met at the end of the second round: (1) a majority (>50%) of experts rating the condition at 3 (somewhat related) or higher, (2) interquartile range (IQR)≤1, and (3) standard deviation (SD)≤1.

From round 1 to round 2, the IQR and SD, respectively, decreased for ratings of 21 of 35 (60%) and 33 of 35 (94%) comorbid conditions for CLABSI, and for 17 of 35 (49%) and 32 of 35 (91%) comorbid conditions for SSI, suggesting improvement in consensus among this group of experts. At the end of round 2, 13 of 35 (37%) and 17 of 35 (49%) comorbid conditions were perceived as causally related to CLABSI and SSI, respectively.

Our results have produced a list of comorbid conditions that should be analyzed as risk factors for and further explored for risk adjustment of CLABSI and SSI.

Infect Control Hosp Epidemiol 2017;38:449–454

To study the relation of preoperative infected urine and postprostatectomy wound infection in patients with and without indwelling bladder catheters.

Patients undergoing prostatectomy were evaluated for the presence of infected urine prior to prostatectomy and postoperative wound infection. They were further divided into patients with indwelling urinary catheter and catheter-free patients. All had received antibiotic prophylaxis.

One hundred fifty consecutive patients undergoing open prostatectomy-mean age was 67 years; 100 patients with an indwelling catheter for a mean period of 50 days; 50 catheter-free patients.

Wound infection was found in 19 of 81 (23.5%) and in 6 of 69 (8.7%) patients with infected and sterile urine, respectively p = .028). In patients with indwelling catheters prior to operation, wound infection was 22.4% when urine was infected and 8.3% when it was not. In patients without catheters, infected urine was associated with 40% of wound infections, as compared with 8.9% of wound infections in patients with sterile urine. Organisms obtained from infected wound and urine were identical in 84% of cases. These results were obtained despite antibiotic prophylaxis.

Wound infection has been demonstrated to be a postprostatectomy complication directly related to the presence of urinary infection at surgery; thus, elective prostatectomy should be deferred until urine becomes sterile.

To study the spread of extended spectrum ß-lactamase-producing, but aminoglycoside-susceptible, Klebsiella pneumoniae strains in our hospital over an 8-month period, by using two genotypic markers.

Ribotyping (using two endonucleases) and randomly amplified polymorphic DNA analysis (RAPD; using two different 10-mer primers) were applied to the epidemiological typing of clinical K pneumoniae isolates from stools, ileal fluid, or urine of hospitalized children.

The surgical intensive care ward (S1: 9 patients, 17 isolates), surgical unit (S2: 2 patients, 2 isolates), and gastroenterology ward (GE: 1 patient, 1 isolate) of the Robert Debre Hospital of Paris, France.

Ribotyping of the 20 clinical isolates, the type strain of the species, and two epidemiologically unrelated isolates with EcoRI and HindlII revealed 6 and 5 different patterns, respectively. Six ribotypes were identified by using these two enzymes. RAPD generated 6 distinct patterns, in complete agreement with ribotyping. Our geno-typic results showed that 11 patients from wards Sl, S2, and GE harbored genotypically related strains, suggesting nosocomial transmission and cross-colonization between and within the three wards.

Ribotyping and RAPD appear to be reliable methods for distinguishing K pneumoniae strains. The spread of one strain of K pneumoniae in different units of our hospital was demonstrated by both methods. However, RAPD has the advantage of simplicity and rapidity conferred by polymerase chain reaction.

Hospital-acquired infections (HAIs) develop rapidly after brief and transient exposures, and ecological exposures are central to their etiology. However, many studies of HAIs risk do not correctly account for the timing of outcomes relative to exposures, and they ignore ecological factors. We aimed to describe statistical practice in the most cited HAI literature as it relates to these issues, and to demonstrate how to implement models that can be used to account for them.

We conducted a literature search to identify 8 frequently cited articles having primary outcomes that were incident HAIs, were based on individual-level data, and used multivariate statistical methods. Next, using an inpatient cohort of incident Clostridium difficile infection (CDI), we compared 3 valid strategies for assessing risk factors for incident infection: a cohort study with time-fixed exposures, a cohort study with time-varying exposures, and a case-control study with time-varying exposures.

Of the 8 studies identified in the literature scan, 3 did not adjust for time-at-risk, 6 did not assess the timing of exposures in a time-window prior to outcome ascertainment, 6 did not include ecological covariates, and 6 did not account for the clustering of outcomes in time and space. Our 3 modeling strategies yielded similar risk-factor estimates for CDI risk.

Several common statistical methods can be used to augment standard regression methods to improve the identification of HAI risk factors.

Infect. Control Hosp. Epidemiol. 2016;37(4):411–419